I have a small off-grid cabin in the woods that I recently purchased. The previous owner had a L14-30 generator connector installed on the outside of the cabin and wired it with normal 120v outlets 4 light sockets I plan to put LED bulbs in. I camp up there maybe once a month and wouldn't use much power; just the lights and maybe charge a laptop to watch a movie, so was looking at getting a solar generator kit (something like the GoalZero Yeti).
What I haven't found is a battery backup system with a L14-30 connector; all the ones i've found so far just have normal 3 prong 5-15 connectors. Can I use a 5-15 to L14-30 connector adapter to run the cabin? Picts of my inlet box connector and circuit breaker box below.